title: The more the merrier: recent hybridization and polyploidy in cardamine.
abstract: This article describes the use of cytogenomic and molecular approaches to explore the origin and evolution of Cardamine schulzii, a textbook example of a recent allopolyploid, in its ~110-year history of human-induced hybridization and allopolyploidy in the Swiss Alps. Triploids are typically viewed as bridges between diploids and tetraploids but rarely as parental genomes of high-level hybrids and polyploids. The genome of the triploid semifertile hybrid Cardamine × insueta (2n = 24, RRA) was shown to combine the parental genomes of two diploid (2n = 2x = 16) species, Cardamine amara (AA) and Cardamine rivularis (RR). These parental genomes have remained structurally stable within the triploid genome over the >100 years since its origin. Furthermore, we provide compelling evidence that the alleged recent polyploid C. schulzii is not an autohexaploid derivative of C. × insueta. Instead, at least two hybridization events involving C. × insueta and the hypotetraploid Cardamine pratensis (PPPP, 2n = 4x-2 = 30) have resulted in the origin of the trigenomic hypopentaploid (2n = 5x-2 = 38, PPRRA) and hypohexaploid (2n = 6x-2 = 46, PPPPRA). These data show that the semifertile triploid hybrid can promote a merger of three different genomes and demonstrate how important it is to reexamine the routinely repeated textbook examples using modern techniques.
authors.affiliation: Research Group Plant Cytogenomics, Central European Institute of Technology (CEITEC), Masaryk University, CZ-62500 Brno, Czech Republic.
authors.forename: Terezie
authors.initials: T
authors.lastname: Mandáková
authors.forename: Ales
authors.initials: A
authors.lastname: Kovarík
authors.forename: Judita
authors.initials: J
authors.lastname: Zozomová-Lihová
authors.forename: Rie
authors.initials: R
authors.lastname: Shimizu-Inatsugi
authors.forename: Kentaro K
authors.initials: KK
authors.lastname: Shimizu
authors.forename: Klaus
authors.initials: K
authors.lastname: Mummenhoff
authors.forename: Karol
authors.initials: K
authors.lastname: Marhold
authors.forename: Martin A
authors.initials: MA
authors.lastname: Lysak
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D031217:Cardamine / Q000235:genetics*; D018628:Gene Dosage; D018745:Genome, Plant / Q000235:genetics*; D042822:Genomic Instability; D006824:Hybridization, Genetic; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D010802:Phylogeny; D011123:Polyploidy; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D057885:Triploidy